The invention relates to systems for airdropping cargo from aircraft, and more particularly to container delivery systems CDS) for airdropping multiple CDS containers at high aircraft speeds.
Airdrops of equipment and supplies from rear opening cargo aircraft, such as C-130's and C-141's, are performed by various different methods to satisfy different requirements.
Low-velocity airdrops are used to airdrop very heavy (greater than 2500 pounds) individual loads from altitudes of 1200 to 1500 feet above ground level. Aircraft speeds are about 130 to 150 knots. The load is attached to a energy absorbing pallet, or platform, which rides on aircraft floor rollers. As extraction parachute pulls the load and pallet from the rear of the aircraft. Recovery parachutes are attached to the load and pallet to lower them at low velocity to the ground.
Low altitude parachute powered ejection systems (commonly called LAPES) are used to airdrop very heavy individual loads with very accurate targeting. The aircraft makes a low altitude approach from about 200 feet altitude and 130 knots airspeed. An extraction parachute pulls out the load and pallet at about a ten foot altitude while the aircraft makes an immediate pullout to clear ground obstacles and establish a desired flight path. A typical low altitude powered ejection system includes an extraction parachute for pulling the load and pallet from the rear of the aircraft, an extraction line for connecting the extraction parachute to the load and pallet, and a command-operated towplate for holding and then releasing a link connecting two sections of the extraction line to precisely begin the airdrop at the proper time.
Low velocity container delivery systems CDS) are used to airdrop multiple medium weight (625 to 2200 pounds) containers, or cargo bundles, from altitudes ranging from 600 feet to 25,000 feet, with 1000 feet the most common altitude. The containers are generally arranged in paired rows on individual energy absorbing pallets riding on aircraft floor rollers. The aircraft is maintained at a sufficient positive deck angle, typically five degrees, so that the containers are removed from the aircraft by gravity. Each container generally has a separate recovery parachute for controllinq descent to the qround. Static lines are generally used to deploy each recovery parachute as each container leaves the aircraft.
High-velocity airdrops allow the dropped containers to fall at only a partially retarded rate, or in complete free fall, to minimize the size of the drop zone required for high altitude drops. Very elaborate energy absorbing pallets are used to prevent destruction to the airdropped articles.
It is desired to perform CDS airdrops at higher aircraft speeds to enhance the survivability of the aircraft in combat environments. Unfortunately, container delivery systems do not work well at high aircraft speeds, primarily due to reduced deck altitudes. Also, the cargo containers in present systems do not exit at predictable times and do not land reliabIy on target. They are especially affected by wind drift.
To be successful, high speed CDS airdrops require increased drop accuracy and more predictable exit times to ensure that the cargo is dropped on target. Additionally, the containers must be grouped together better than is presently done to reduce scatter on the ground.
It is seen, therefore, that there is a need for an improved container delivery system that is particularly suitable for high speed airdrops.
It is, therefore, a principal object of the invention to provide a container delivery system that has high drop accuracy with predictable exit times, and that drops its containers with minimum scatter.
It is another object of the invention to provide an extraction parachute powered mechanism for removing CDS containers at high aricraft speeds.
It is yet another object of the invention to provide an improved mechanism and method for automatically disconnecting the extraction line and parachute after the airdrop has been completed.
It is a further object of the invention to use to the greatest possible extent existing components from other airdrop systems.
It is a feature of the invention that it provides for emergency release of the extraction line in the event the system jams.
It is an advantage of the invention that it provides tight grouping of the containers as they exit the aircraft.